An aircraft wing is constructed from a plurality of spaced ribs that are joined by spars which run along the length of the wing and attach to the fuselage. Stringers are joined to the outer surfaces of the ribs to support the outer skin of the wing.
The space within an aircraft's wing, between the ribs and within the skin, is utilised to store aviation fuel. The fuel is sealed within the skin of the wing and may pass through openings in the structural members of the wings, such as the ribs and spars. A wing used to store fuel will also have a fuel system having the necessary components for monitoring and handling the fuel. Such components may include pumps, valves and sensors as well as other equipment to monitor and control the fuel. Some ribs have openings in them to allow fuel to move through the ribs, however, other ribs may be sealed to create separate fuel storage areas within the wing. Typically, sensors are positioned on ribs to gauge the amount of fuel remaining in that storage area.
Currently, fuel system components are installed into the wing during the final wing manufacturing process after the skins, ribs, spars and stringers are fixed together. This installation process is problematic because once the wing is fully, or even partly assembled, access to the fuel storage areas is inhibited and the installation work is labour intensive which may reduce the quality of installation and therefore the reliability of the fuel system.
Furthermore, cables and pipes for connecting the fuel system have to take indirect or arduous paths through the wing, sometimes including a path through a penetration in the wing skin and over outer surfaces of the aircraft, such as for electrical boost pumps. The cables may be exposed to damage from foreign objects within the fuel storage areas, within the wing and outside of the aircraft. Moreover, cable harnesses on outer surfaces of an aircraft can cause undesirable aerodynamic effects.
To install the components within the wing, the connecting cables may need to be deformed around bends and within the confined spaces of the wing. This may cause damage to the components and cables during installation.
Similar problems will recur throughout the life of the fuel system during maintenance and repair. Access will remain difficult and parts of the wing may need to be disassembled to replace components.